H1B file后多久可以收到physical receipt notice？

Hi 各位好！ 我最近做H1B transfer，都file一周了，律师收到了 an email notice for both H-1B petition was received by USCIS, and also approved by USCIS. 请问什么时候可以收到 an official physical receipt notice 呢？ 我用receipt就可以入职，不用等 approval notice。现在已离职，比较捉急，提前谢谢大家提供数据哈。